title: Influence of skin extension upon the epidermal morphometry, an in vivo study.
abstract: BACKGROUND
  The Dermal-Epidermal Junction (DEJ) is characterized by undulations whose apices are called papillae. With aging, epidermis becomes thinner, together with a flattening of the DEJ, leading to a decreased density of papillae. The causes of these modifications are likely as multiple as uncertain. The present paper deals with in vivo morphometric characterization of the DEJ and its changes following a skin surface deformation.
  
  
  METHODS
  Living epidermis of human adults was examined by means of in vivo Reflectance Confocal Microscopy. Distances between skin surface and papillae apex and pegs of the DEJ were, respectively, recorded in both relaxed and stretched skin situation. The number of papillae present within a single image (field of view, 500 × 500 μm) was also measured.
  
  
  RESULTS
  Skin extension has no effect upon the distance between skin surface and the apex of papillae. In contrast, the distance between skin surface and the pegs of papillae decreases. On the other hand, skin extension leads to a significant decrease in the number of papillae within a single image.
  
  
  CONCLUSIONS
  Epidermal atrophy and structural changes observed in the DEJ with aging may be, by some extent, related to daily and repetitive skin deformations all along the life span.
authors.affiliation: Consultant, l'Oréal Recherche, Chevilly-Larue, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Lévêque
authors.forename: Ferial
authors.initials: F
authors.lastname: Fanian
authors.forename: Philippe
authors.initials: P
authors.lastname: Humbert
mesh_terms: D000328:Adult; D020405:Dermis / Q000166:cytology* / Q000502:physiology*; D046169:Dermoscopy / Q000379:methods*; D055119:Elastic Modulus / Q000502:physiology; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology*; D005260:Female; D006244:Hardness / Q000502:physiology; D006245:Hardness Tests; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D010812:Physical Stimulation / Q000379:methods; D013718:Tensile Strength / Q000502:physiology; D055815:Young Adult
keywords: Dermal-Epidermal Junction; Living epidermis; flattening; in vivo reflectance confocal microscopy; stretched skin